For a video using the High Efficiency Video Coding (HEVC) standard, there is a requirement for acquiring a regional picture from the video in a video playback process. For example, FIG. 1 is a schematic diagram of a scenario in which a regional picture in a video needs to be acquired. A European Cup match is shot using a panoramic shooting technology, and a shot panoramic video has a resolution of 6 kilo (K)×2K. The video with this resolution is suitable for playback on a panoramic display with an ultra-high resolution. If a user wants to view this panoramic video on a common screen, because of a low resolution of the common screen, a regional picture from the panoramic video needs to be acquired before the regional picture can be played on the common screen. As shown in FIG. 1, an upper part is a panoramic screen, and a lower part is a mobile phone screen and a computer screen. The panoramic screen can display a complete video picture, but neither the mobile phone screen nor the computer screen can display a complete panoramic video picture. Therefore, during playback on the mobile phone screen or the computer screen, a regional picture similar to that shown in a dashed block region in FIG. 1 needs to be acquired first, and then the regional picture is displayed on the mobile phone screen or the computer screen.
For another example, FIG. 2 is a schematic diagram of another scenario in which a regional picture in a video needs to be acquired. In video surveillance, pictures shot by multiple cameras may be spliced to form one surveillance video. During playback of the surveillance video, a user needs to acquire a regional picture of the surveillance video for playback if the user needs to specify a picture shot by one camera of the multiple cameras for playback. As shown in FIG. 2, a surveillance video is on the left side. Each image in the video includes pictures shot by multiple cameras. When it is assumed that a region identified by a dashed block is a regional picture specified by a user, the regional picture needs to be acquired for independent playback.
The HEVC introduces a concept of a region that can be independently decoded. The region that can be independently decoded may be a rectangular region in a video picture. Because video content within this region can be decoded independently, the user can independently request the video content in this region. Furthermore, as shown in FIG. 3, a region in a dashed block is the region that can be independently decoded. The user may request to play entire video content in a terminal screen, or may request to play video content only in the dashed block.
The Dynamic Adaptive Streaming over Hypertext Transfer Protocol (DASH) technology combines features of progressive downloading and playback in a conventional streaming technology and the HyperText Transfer Protocol (HTTP).
A DASH system may include a DASH server and a DASH terminal. The DASH server mainly stores two parts of content, media presentation description (MPD) and media. The MPD records media information such as a media segment address using the Extensible Markup Language (XML). The media may be media content such as a video or an audio. A video is used as an example. The video includes a media segment. Each media segment corresponds to a section of video content. Each media segment also corresponds to one segment address. The segment address is an HTTP network address and is also referred to as an acquiring address of the media segment. The DASH terminal may acquire the segment address by parsing the MPD, and acquire, from the DASH server using the acquired segment address, video content corresponding to the media segment.
In the prior art, to implement playback of a region in a video picture, a DASH server needs to independently store, in advance, content of a partial video of which a region needs to be played, that is, both content of the partial video and content of a panoramic video need to be stored independently in the DASH server. Consequently, the DASH server stores excessive redundant information, wasting a storage resource of the DASH server.